Greetings. I recently purchased an iPad 2 at 6.1.2. Fortunately, the previous owner saved the hashes for 4.3.5, 5.1.1, 6.1.2 et al. in between. Using the procedure in described on iClarified, I was able to successfully downgrade from 6.1.2 to 5.1.1 using Redsn0w and then Jailbreak with Absinthe. So far so good.

I would like to switch to T-Mobile but it appears that the iPad managed to get relocked to AT&T. When I put the T-Mobile sim in the device, it still indicates AT&T 12.0 as the carrier after a reboot (T-Mobile guy said it sometimes gets relocked during a restore in iTunes). I called AT&T to get it re-unlocked and they said that the network was set up to allow it to unlock and that I should backup and "restore" my iPad. Option-clicking the "restore" pulldown in iTunes tells me that it will erase and reinstall 5.1.1. But since Apple is no longer signing 5.1.1, I'll have to do it from a locally stored IPSW for 5.1.1 and Apple shouldn't know about it right? In addition, it takes an hour or 2 (or 3) to reinstall the OS, sync, Jailbreak, add all the Cydia apps etc. so I don't want to do this capriciously. Is this correct? Should I go through this entire process again? Or am I now SOL until I return to the current signed iOS. BTW, one Apple tech support person told me that the iPads are carrier specific and it couldn’t be done. Was he wrong? I'm now completely confused!